How Much Does a Sump Pump Cost to Run? (2026 Data)

Most appliances have a predictable monthly cost because their runtime is predictable. A refrigerator cycles the same amount whether it rains or not. A sump pump is different. It sits idle until the water table rises or rain saturates the soil around the foundation, then the float switch trips and the motor runs until the pit drains. In a dry July, that might happen a few times a day for a couple of minutes each. In a stormy June, the pump can cycle continuously for hours.

At the April 2026 US average rate of 18.05 cents per kWh from the EIA Electric Power Monthly, a typical 800-watt pump running 12 minutes a day uses 4.8 kWh a month and costs 87 cents. The same pump running two hours a day uses 48 kWh and costs $8.66. At four hours a day during heavy rain, 96 kWh and $17.33. The wattage never changed. Only the weather did.

Sump pumps are sized by horsepower. The wattage tracks with it. At two hours of runtime per day, a reasonable average for a month with regular rain, the cost ladder looks like this at the US average rate:

1/3 HP (540 watts): 32.4 kWh, $5.85 a month. The Zoeller M53 and Superior Pump 92301 both land here. Handles a standard basement with moderate groundwater. 1/2 HP (800 watts): 48 kWh, $8.66 a month. The most common residential size. Enough for most basements with seasonal water. 3/4 HP (1,110 watts): 66.6 kWh, $12.02 a month. The WAYNE CDU980E class. High-water-table homes where the pump runs harder and more often.

In dry weather at 12 minutes a day, those same pumps cost $0.59, $0.87, and $1.20 a month. The horsepower difference barely registers when the pump is idle most of the day. It only matters during the months when the pump actually works.

A sump pump does not run continuously even during a rainstorm. It cycles: the pit fills, the float trips, the pump evacuates the water, then it shuts off until the pit fills again. A common pattern during moderate rain is five minutes on, twenty-five minutes off. That is one sixth of continuous runtime.

An 800-watt pump cycling five-on, twenty-five-off for six hours during a storm day runs about one hour total. That costs 14 cents. The same pump running six hours straight would cost 87 cents. Six times the electricity, same storm, same pump, because the pit never got a chance to drain between cycles.

If your pump runs continuously during rain and never cycles off, the pit is filling faster than the pump can empty it. That is a sizing problem, not an electricity problem. A properly sized pump cycles. An undersized pump runs flat out and still loses ground.

Battery backup sump pumps have a trickle charger that draws 3 to 5 watts around the clock to keep the battery topped off. At 3 watts, that is 26.3 kWh a year and $4.74 in electricity. At 5 watts, 43.8 kWh and $7.91. Comparable to leaving a standby device plugged in.

The real cost of a battery backup is the battery itself. Lead-acid batteries last three to five years and cost $100 to $200 to replace. That is $20 to $67 a year in replacement costs, dwarfing the $5 to $8 in trickle-charger electricity. The charger runs on pennies. The battery runs on calendar time, and it is going to need replacing whether you lose power or not.

During an actual outage the backup pump runs on stored battery charge, drawing zero from the grid. The electricity cost during the event itself is zero. The cost you already paid is the years of trickle charging and the battery sitting in the pit aging.

An 800-watt pump running two hours a day uses 48 kWh a month everywhere. The rate is the only variable:

Louisiana (12.44¢/kWh): $5.97. Texas (14.80¢/kWh): $7.10. US average (18.05¢/kWh): $8.66. New York (24.40¢/kWh): $11.71. California (31.01¢/kWh): $14.88. Hawaii (39.79¢/kWh): $19.10.

Hawaii costs 3.2 times Louisiana for the same pump doing the same work. In high-rate states, a wet spring on a 3/4 HP pump can cost more per month than a pond pump running around the clock, because the sump pump draws three to ten times the wattage when it is on. Every state's 2026 rate is in the state rates guide.

In a dry month, a sump pump is invisible on the bill. Under a dollar for most homes. You would not notice it next to the refrigerator or the heavy hitters. It sits in the basement doing nothing, costing nothing.

In a wet month, it shows up. Eight to seventeen dollars for a typical pump, more for a 3/4 HP unit in a high-water-table area. Not devastating, but enough to notice on a bill that also includes the AC running harder because summer storms come with heat. The pump and the cooling system tend to spike together.

The lever you can pull is maintenance, not settings. A clean pit, a working check valve, and gutters directed away from the foundation all reduce how often and how long the pump cycles. A failed check valve forces the pump to re-lift water it already moved, roughly doubling runtime and cost. Replacing a $15 check valve every three to five years is the cheapest thing you can do for the electricity bill and the pump's lifespan.

To put a number on your own setup, the sump pump calculator takes your pump's wattage, your runtime estimate, and your local rate, and returns the monthly and yearly cost. For a pump that runs more in some months than others, try it twice: once for dry weather, once for storm season. The gap between those two numbers is the real cost of owning a basement.